JP4586922B2 - Photosensitive resin composition and photosensitive element using the same - Google Patents

Description

  The present invention relates to a photosensitive resin composition and a photosensitive element using the same.

  In the printed wiring board manufacturing industry, conventionally, a solder resist is formed on a printed wiring board. This solder resist has a role to prevent solder from adhering to unnecessary portions of the conductor layer of the printed wiring board in the soldering process for bonding the mounted part to the printed wiring board. When the printed wiring board is used later, it also serves as a permanent mask for preventing corrosion of the conductor layer and maintaining electrical insulation between the conductor layers.

  As a method for forming a solder resist, for example, a method of screen printing a thermosetting resin on a conductor layer of a printed wiring board is known. However, since such a method has a limit in increasing the resolution of the resist pattern, it has become difficult to cope with the recent increase in the density of printed wiring boards.

  Therefore, in order to achieve high resolution of the resist pattern, the photoresist method has been actively used. In this photoresist method, a photosensitive resin composition layer made of a photosensitive resin composition is formed on a substrate, the photosensitive resin composition layer is cured by exposure of a predetermined pattern, and unexposed portions are removed by development. Thus, a cured film having a predetermined pattern is formed.

  In addition, the photosensitive resin composition used in such a method is mainly an alkali development type that can be developed with a dilute aqueous alkali solution such as an aqueous sodium carbonate solution from the viewpoint of conservation of the working environment and global environment. .

As such a photosensitive resin composition, for example, a liquid resist ink composition described in Patent Document 1 below and a photosensitive thermosetting resin composition described in Patent Document 2 below are known.
JP-A 61-243869 Japanese Patent Laid-Open No. 01-141904

  By the way, in recent years, regulations on flame retardancy of various industrial products against fire have become stricter, and materials used for printed wiring boards and the like are no exception. As a flame retardant method, a method of adding a halogen compound, an antimony compound, a phosphorus compound, a boron compound, an inorganic filler or the like to a material is generally known.

  However, recently, with increasing interest in environmental issues and human safety issues, the focus has shifted to non-polluting, low toxic and safety, not only flammable but also harmful gases and fuming substances. Reduction is being demanded. In response, flame retardant substrates that do not use halogen compounds or antimony compounds have already been developed and put into practical use.

  However, when a cured film is formed on a flame retardant substrate as described above using a conventional photosensitive resin composition as described in Patent Documents 1 and 2, sufficient flame retardancy (preferably, (UL94 VTM-0 level) cannot be ensured by examination by the present inventors.

  This invention is made | formed in view of the said situation, and it aims at providing the photosensitive resin composition which can form the cured film excellent in the flame retardance while having the outstanding alkali developability. Moreover, an object of this invention is to provide the photosensitive element provided with the photosensitive resin composition layer which consists of such a photosensitive resin composition.

  As a result of intensive studies to achieve the above object, the present inventors have found that the above object can be achieved by including a resin having a specific structure and a phosphorus-containing compound in a photosensitive resin composition. The present invention has been completed.

That is, the present invention provides (A) a novolak-type acid-modified vinyl group-containing epoxy resin having a biphenyl skeleton, (B) a phosphorus-containing compound, and (C) a photopolymerization having at least one ethylenically unsaturated group in the molecule. A photosensitive resin composition containing a phosphinic acid salt represented by the following general formula (2), wherein the (B) phosphorus-containing compound comprises: .

  According to this photosensitive resin composition, by having the said structure, while having the outstanding alkali developability, the cured film can obtain the outstanding flame retardance. Therefore, the said photosensitive resin composition can be used suitably for manufacture of the printed wiring board etc. in which a flame retardance is requested | required.

［式（１）中、Ｒ^１及びＲ^２は各々独立に、水素原子、炭素数１〜８のアルキル基、又は、アリール基を示し、ｎは０〜５０の整数を示す。なお、式（１）中、複数存在するＲ^１及びＲ^２はそれぞれ同一でも異なっていてもよい。］In the photosensitive resin composition of the present invention, the (A) epoxy resin includes (a) an epoxy resin represented by the following general formula (1), (b) an unsaturated group-containing monocarboxylic acid, ( c) It preferably contains an acid-modified vinyl group-containing epoxy resin which is a reaction product with a polybasic carboxylic acid anhydride.

[In Formula (1), R ¹ and R ² each independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an aryl group, and n represents an integer of 0 to 50. In formula (1), a plurality of R ¹ and R ² may be the same or different. ]

  (A) By including the above-mentioned specific acid-modified vinyl group-containing epoxy resin as an epoxy resin, the photosensitive resin composition provides excellent alkali developability and forms a cured film having more excellent flame retardancy. It becomes possible.

  Moreover, it is preferable that the photosensitive resin composition of this invention contains (E) thermosetting agent further. When the photosensitive resin composition contains (E) a thermosetting agent, the photosensitive resin composition is photocured and then further thermoset to further improve the insulation reliability of the resulting cured film. Can do.

［式（２）中、Ａ及びＢは各々独立に、直鎖状又は分枝状の炭素数１〜６のアルキル基、又は、アリール基を示し、ＭはＭｇ、Ｃａ、Ａｌ、Ｓｂ、Ｓｎ、Ｇｅ、Ｔｉ、Ｚｎ、Ｆｅ、Ｚｒ、Ｃｅ、Ｂｉ、Ｓｒ、Ｍｎ、Ｌｉ、Ｎａ及びＫからなる群より選択される少なくとも一種の金属を示し、ｍは１〜４の整数を示す。］ Further, in the photosensitive resin composition of the present invention, the (B) phosphorus-containing compound, including a phosphinic acid salt represented by the following general formula (2).

[In Formula (2), A and B each independently represent a linear or branched alkyl group having 1 to 6 carbon atoms or an aryl group, and M represents Mg, Ca, Al, Sb, Sn. , Ge, Ti, Zn, Fe, Zr, Ce, Bi, Sr, Mn, Li, Na, and K. m represents an integer of 1 to 4. ]

  When the photosensitive resin composition contains the phosphinic acid salt represented by the general formula (2), the flame retardancy of the obtained cured film can be further improved.

  Moreover, the photosensitive resin composition of this invention WHEREIN: It is preferable that the said (B) phosphorus containing compound contains phosphate ester. When the photosensitive resin composition contains a phosphate ester, the flame retardancy and flexibility of the obtained cured film can be further improved. In addition, it is preferable that the photosensitive resin composition of this invention contains both the phosphinate represented by the said General formula (2) and the said phosphate ester as (B) phosphorus containing compound, Thus, both the flame retardancy and flexibility of the obtained cured film can be made particularly excellent.

  In the photosensitive resin composition of the present invention, the phosphorus-containing compound (B) preferably contains a phenoxyphosphazene compound. By including the phenoxyphosphazene compound in the photosensitive resin composition, the flame retardancy and flexibility of the resulting cured film can be further improved and bleeding out (bleeding out of the photosensitive resin composition) Can be made better. In addition, it is preferable that the photosensitive resin composition of this invention contains both the phosphinic acid salt represented by the said General formula (2), and the said phenoxyphosphazene compound as (B) phosphorus containing compound. Thereby, the flame retardancy, flexibility and bleed-out property of the cured film obtained can be made particularly excellent.

  Furthermore, the photosensitive resin composition of the present invention is preferably for forming a cured film serving as a permanent mask on a flexible substrate.

  The present invention also provides a photosensitive element comprising a support and a photosensitive resin composition layer comprising the above-described photosensitive resin composition of the present invention formed on the support. According to such a photosensitive element, by providing the photosensitive resin composition layer composed of the photosensitive resin composition, an excellent alkali developability can be obtained, and a cured film having excellent flame retardancy can be formed. is there.

  ADVANTAGE OF THE INVENTION According to this invention, while having the outstanding alkali developability, the photosensitive resin composition which can form the cured film excellent in the flame retardance, and the photosensitive element using the same can be provided.

It is a schematic cross section which shows suitable one Embodiment of the photosensitive film of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Photosensitive element, 10 ... Support body, 14 ... Photosensitive resin composition layer.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings as the case may be. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted. In the present invention, (meth) acrylic acid means acrylic acid and methacrylic acid corresponding thereto, (meth) acrylate means acrylate and corresponding methacrylate, (meth) acryloyl group means acryloyl group and The corresponding methacryloyl group is meant.

(Photosensitive resin composition)
The photosensitive resin composition of the present invention comprises (A) a novolak acid-modified vinyl group-containing epoxy resin having a biphenyl skeleton (hereinafter sometimes referred to as “component (A)”), and (B) a phosphorus-containing compound (hereinafter, referred to as “a”). (Sometimes referred to as “component (B)”), (C) a photopolymerizable compound having at least one ethylenically unsaturated group in the molecule (hereinafter sometimes referred to as “component (C)”), and (D) A photopolymerization initiator (hereinafter referred to as “component (D)” in some cases). The photosensitive resin composition of the present invention preferably further contains (E) a thermosetting agent (hereinafter, sometimes referred to as “component (E)”).

  When the photosensitive resin composition of the present invention contains the components (A) to (D), development with a dilute alkaline aqueous solution is possible, and a cured film obtained by curing the photosensitive resin composition. The flame retardancy of can be satisfied at a high level. Therefore, according to the photosensitive resin composition of the present invention, a cured film having sufficient flame retardancy can be efficiently formed with high resolution.

  Further, according to the photosensitive resin composition of the present invention, since the flame retardancy of the cured film can be made sufficiently high without containing a halogen compound or an antimony compound, for example, the environmental load of a printed wiring board And toxicity can be reduced. In particular, when the photosensitive resin composition of the present invention is applied to a non-halogen-based or non-antimony-based flame retardant substrate, the above-described effects are more effectively exhibited.

  Hereinafter, each component contained in the photosensitive resin composition of the present invention will be described.

<(A) component: acid-modified vinyl group-containing epoxy resin>
The novolak acid-modified vinyl group-containing epoxy resin having a biphenyl skeleton as component (A) is preferably (a) an epoxy resin represented by the following general formula (1), and (b) an unsaturated group-containing monocarboxylic acid. It is obtained as a reaction product of an acid and (c) a polybasic carboxylic acid anhydride.

［式（１）中、Ｒ^１及びＲ^２は各々独立に、水素原子、炭素数１〜８のアルキル基、又は、アリール基を示し、ｎは０〜５０の整数を示す。なお、式（１）中、複数存在するＲ^１及びＲ^２はそれぞれ同一でも異なっていてもよい。］

[In Formula (1), R ¹ and R ² each independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an aryl group, and n represents an integer of 0 to 50. In formula (1), a plurality of R ¹ and R ² may be the same or different. ]

  By incorporating the epoxy resin (A) composed of a compound having a structure such as the general formula (1) into the photosensitive resin composition, both alkali developability and flame retardancy can be achieved. .

  Specific examples of (b) unsaturated bond-containing monocarboxylic acid constituting the acid-modified vinyl group-containing epoxy resin as component (A) include, for example, acrylic acid, dimer of acrylic acid, methacrylic acid, β-styryl. Acrylic acid, β-furfurylacrylic acid, crotonic acid, α-cyanocinnamic acid, cinnamic acid, and a saturated or unsaturated dibasic acid anhydride and a (meth) acrylate derivative having one hydroxyl group in one molecule; And half-esters that are a reaction product of a saturated or saturated dibasic acid and an unsaturated group-containing monoglycidyl compound.

  Half esters include, for example, succinic anhydride, maleic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, itaconic anhydride, methylendomethylenetetrahydro Saturated or unsaturated dibasic acid anhydrides such as phthalic anhydride, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, glycerin di (meth) Acrylate, trimethylolpropane di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, (meth) acrylic of phenylglycidyl ether Half esters obtained by reacting (meth) acrylate derivatives having one hydroxyl group in one molecule such as a salt with an equimolar ratio, or saturated or unsaturated dibasic acids (for example, succinic acid , Maleic acid, adipic acid, phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, itaconic acid, fumaric acid, etc.) and an unsaturated group-containing monoglycidyl compound (for example, glycidyl (meth) acrylate, etc.) A half ester obtained by reacting at a ratio.

  These (b) morphanobonic acids can be used singly or in combination of two or more. Particularly preferred (b) monocarboxylic acid is acrylic acid.

  Specific examples of (c) polybasic carboxylic acid anhydride constituting the acid-modified vinyl group-containing epoxy resin as component (A) include, for example, maleic anhydride, succinic anhydride, phthalic anhydride, and tetrahydrophthalic anhydride. Hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride and the like.

  (A) It is preferable that the acid value of a component is 60-150 mgKOH / g, and it is more preferable that it is 80-120 mgKOH / g. When the acid value is less than 60 mgKOH / g, development with dilute alkali aqueous solution tends to be difficult, and when it exceeds 150 mgKOH / g, the insulation reliability, chemical resistance and plating resistance of the resulting cured film tend to be insufficient. There is.

  In addition, the acid value of (A) component can be measured with the following method. First, after accurately weighing about 1 g of the resin solution as the component (A), 30 g of acetone is added to the resin solution to uniformly dissolve the resin solution. Next, an appropriate amount of phenolphthalein as an indicator is added to the solution, and titration is performed using a 0.1N aqueous KOH solution. Then, the acid value is calculated from the titration result by the following formula.

  In the formula, A represents the acid value (mgKOH / g), Vf represents the titration amount (mL) of phenolphthalein, Wp represents the mass (g) of the resin solution as the component (A), and I Indicates the ratio (% by mass) of the non-volatile content of the resin solution as the component (A).

  The weight average molecular weight of the component (A) is not particularly limited, but is preferably 1000 to 50000, more preferably 2000 to 30000, and more preferably 3000 to 15000 from the viewpoint of film properties and resolution. It is particularly preferred.

  The (A) component novolak-type acid-modified vinyl group-containing epoxy resin having a biphenyl skeleton can be purchased as a commercial product, for example, ZCR-1569H, ZCR-1596H, ZCR-1611H, ZCR-1610H (all Nippon Kayaku Co., Ltd., trade name) can also be used.

  In addition, the photosensitive resin composition of the present invention includes a phenol novolac acid-modified vinyl group-containing epoxy resin, a cresol novolac acid-modified vinyl group-containing epoxy resin, a bisphenol A-type acid-modified vinyl group-containing epoxy resin, and a bisphenol F-type acid-modified. Acid-modified vinyl group-containing epoxy resins other than novolac-type acid-modified vinyl group-containing epoxy resins having a biphenyl skeleton such as vinyl group-containing epoxy resins, acrylic resins, styrene resins, epoxy resins, amide resins, amide epoxy resins, Alkyd resins and phenol resins can be added and used. Among these, it is preferable to use an acrylic resin from the viewpoint of imparting film properties.

  The acrylic resin is preferably a resin containing (meth) acrylic acid and (meth) acrylic ester as constituent monomers, and radically polymerizes the constituent monomer containing (meth) acrylic acid and (meth) acrylic ester. Can be manufactured.

  Examples of the (meth) acrylic acid ester include compounds represented by the following general formula (3) and those in which the alkyl group of the compound is substituted with a hydroxyl group, an epoxy group, a halogen, or the like.

In the general formula ^{(3), R 11} represents a hydrogen atom or a methyl ^{group, R 12} represents an alkyl group, an alicyclic hydrocarbon group or a benzyl group having 5 to 10 carbon atoms having 1 to 12 carbon atoms. Examples of the alkyl group represented by R ¹² include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, and a dodecyl group. And structural isomers thereof.

  When the novolac acid-modified vinyl group-containing epoxy resin having a biphenyl skeleton as the component (A) and the acrylic resin are used in combination, the weight average molecular weight of the acrylic resin is from 30,000 to It is preferably 300,000, more preferably 40,000 to 200,000, and particularly preferably 50,000 to 150,000.

<(B) component: phosphorus-containing compound>
The phosphorus-containing compound as component (B) preferably contains a phosphinic acid salt represented by the following general formula (2).

［式（２）中、Ａ及びＢは各々独立に、直鎖状又は分枝状の炭素数１〜６のアルキル基、又は、アリール基を示し、ＭはＭｇ、Ｃａ、Ａｌ、Ｓｂ、Ｓｎ、Ｇｅ、Ｔｉ、Ｚｎ、Ｆｅ、Ｚｒ、Ｃｅ、Ｂｉ、Ｓｒ、Ｍｎ、Ｌｉ、Ｎａ及びＫからなる群より選択される少なくとも一種の金属を示し、ｍは１〜４の整数を示す。］

[In Formula (2), A and B each independently represent a linear or branched alkyl group having 1 to 6 carbon atoms or an aryl group, and M represents Mg, Ca, Al, Sb, Sn. , Ge, Ti, Zn, Fe, Zr, Ce, Bi, Sr, Mn, Li, Na, and K. m represents an integer of 1 to 4. ]

  Here, as specific examples of A and B in the formula (2), for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, tert-butyl group, n-pentyl group, phenyl Groups and the like.

  Moreover, 80 mass% or more of the phosphinic acid salt represented by the general formula (2) has a particle size of the phosphinic acid salt particles from the viewpoint of reliability when used in the photosensitive resin composition and the photosensitive element. It is preferably 10 μm or less, more preferably 5 μm or less, and particularly preferably 3 μm or less. When the particle size of the particles exceeds 10 μm, the appearance of the coating film of the photosensitive resin composition tends to be deteriorated, and the production of a high-resolution printed wiring board tends to be difficult.

  Said phosphinic acid salt can be used individually by 1 type or in combination of 2 or more types. Moreover, the said phosphinic acid salt can also be purchased as a commercial item, for example, EXOLIT OP 930, EXOLIT OP 935, EXOLIT OP 940 (all are the brand names made by Clariant) can also be used.

  When the photosensitive resin composition contains the phosphinate as the component (B), a cured film obtained by curing the photosensitive resin composition can obtain more sufficient flame retardancy. In addition, the phosphinate represented by the general formula (2) has a structure that is difficult to hydrolyze, and can effectively prevent the generation of ionic impurities that reduce electrical insulation, so that the cured film is excellent. It can have insulation reliability.

  Moreover, it is also preferable that the phosphorus-containing compound as the component (B) contains a phosphate ester. Specific examples of phosphate esters include, for example, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate, 1,3-dihydroxybenzene / trichlorophosphine polycondensate phenol Examples thereof include a condensate and a phenol condensate of 2,2-bis (p-hydroxyphenyl) propane / trichlorophosphine oxide polycondensate. These are commercially available, for example, TPP, TCP, TXP, CDP, XDP, CR-733S, CR-741, CR-747 (all are trade names manufactured by Daihachi Chemical Co., Ltd.), PFR, FP -600 and FP-700 (both manufactured by Adeka, trade names) and the like.

  When the photosensitive resin composition contains a phosphate ester as the component (B), the flame retardancy of a cured film obtained by curing the photosensitive resin composition can be further improved. Moreover, since the phosphate ester functions as a plasticizer, the flexibility of the cured film can be further improved.

  Moreover, it is also preferable that the phosphorus-containing compound as the component (B) includes a phenoxyphosphazene compound. Specific examples of the phenoxyphosphazene compound include a compound having a cyclic structure represented by the following general formula (4) and / or a compound having a chain structure represented by the following general formula (5).

［式（４）中、ｒは１〜２０の整数を示す。］

[In Formula (4), r shows the integer of 1-20. ]

［式（５）中、ｓは１〜２０の整数を示す。］

[In Formula (5), s shows the integer of 1-20. ]

  When the photosensitive resin composition contains a phenoxyphosphazene compound as the component (B), the flame retardancy of a cured film obtained by curing the photosensitive resin composition can be further improved. In addition, the phenoxyphosphazene compound can improve the flexibility and bleed-out property (bleeding out of the photosensitive resin composition) of the cured film.

  As the component (B), at least one of the phosphinic acid salt represented by the general formula (2), the phosphate ester, and the phenoxyphosphazene compound may be used alone, but at least the general formula It is preferable to use the phosphinic acid salt represented by (2), and it is particularly preferable to use the phosphinic acid salt represented by the general formula (2) in combination with the phosphate ester or the phenoxyphosphazene compound. Moreover, as a (B) component, well-known phosphorus containing compounds other than these can also be used.

<(C) component: a compound having at least one ethylenically unsaturated bond>
(C) Specific examples of the photopolymerizable compound having at least one ethylenically unsaturated group in the molecule include, for example, a bisphenol A (meth) acrylate compound; an α, β-unsaturated carboxylic acid in a polyhydric alcohol. Compound obtained by reaction; Compound obtained by reacting glycidyl group-containing compound with α, β-unsaturated carboxylic acid; Urethane monomer or urethane oligomer such as (meth) acrylate compound having urethane bond, etc. Nonylphenoxy polyoxyethylene acrylate; γ-chloro-β-hydroxypropyl-β ′-(meth) acryloyloxyethyl-o-phthalate, β-hydroxyalkyl-β ′-(meth) acryloyloxyalkyl-o- Phthalates such as phthalates; alkyl (meth) acrylates Le, EO-modified nonylphenyl (meth) acrylate or the like can be exemplified. These can be used individually by 1 type or in combination of 2 or more types.

  Examples of bisphenol A-based (meth) acrylate compounds include 2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane and 2,2-bis (4-((meth) acryloxypolypropoxy). ) Phenyl) propane, 2,2-bis (4-((meth) acryloxypolybutoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypolyethoxypolypropoxy) phenyl) propane, etc. Can be mentioned.

  Examples of 2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane include 2,2-bis (4-((meth) acryloxydiethoxy) phenyl) propane, 2,2- Bis (4-((meth) acryloxytriethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxytetraethoxy) phenyl) propane, 2,2-bis (4-((meth)) Acryloxypentaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyhexaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyheptaethoxy) phenyl) propane 2,2-bis (4-((meth) acryloxyoctaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxy nonaethoxy) ) Phenyl) propane, 2,2-bis (4-((meth) acryloxydecaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyundecaethoxy) phenyl) propane, 2, 2-bis (4-((meth) acryloxydodecaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxytridecaethoxy) phenyl) propane, 2,2-bis (4- ( (Meth) acryloxytetradecaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypentadecaethoxy) phenyl) propane and 2,2-bis (4-((meth) acryloxyhexa) Decaethoxy) phenyl) propane and the like. Of these, 2,2-bis (4- (methacryloxypentaethoxy) phenyl) propane is commercially available as BPE-500 (trade name, manufactured by Shin-Nakamura Chemical Co., Ltd.). 4- (Methacryloxypentadecaethoxy) phenyl) propane is commercially available as BPE-1300 (trade name, manufactured by Shin-Nakamura Chemical Co., Ltd.). These can be used individually by 1 type or in combination of 2 or more types.

  Examples of 2,2-bis (4-((meth) acryloxypolypropoxy) phenyl) propane include 2,2-bis (4-((meth) acryloxydipropoxy) phenyl) propane, 2,2- Bis (4-((meth) acryloxytripropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxytetrapropoxy) phenyl) propane, 2,2-bis (4-((meth)) Acryloxypentapropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyhexapropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyheptapropoxy) phenyl) propane 2,2-bis (4-((meth) acryloxyoctapropoxy) phenyl) propane, 2,2-bis (4-((meth) acrylic) Xinonapropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxydecapropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyundecapropoxy) phenyl) propane 2,2-bis (4-((meth) acryloxydodecapropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxytridecapropoxy) phenyl) propane, 2,2-bis ( 4-((meth) acryloxytetradecapropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypentadecapropoxy) phenyl) propane and 2,2-bis (4-((meth)) And acryloxyhexadecapropoxy) phenyl) propane. These can be used individually by 1 type or in combination of 2 or more types.

  Examples of 2,2-bis (4-((meth) acryloxypolyethoxypolypropoxy) phenyl) propane include 2,2-bis (4-((meth) acryloxydiethoxyoctapropoxy) phenyl) propane, Examples include 2,2-bis (4-((meth) acryloxytetraethoxytetrapropoxy) phenyl) propane and 2,2-bis (4-((meth) acryloxyhexaethoxyhexapropoxy) phenyl) propane. These can be used individually by 1 type or in combination of 2 or more types.

  Examples of the compound obtained by reacting an α, β-unsaturated carboxylic acid with a polyhydric alcohol include 2 to 14 polyethylene glycol di (meth) acrylate propylene groups having 2 to 14 ethylene groups. Polypropylene glycol di (meth) acrylate, polyethylene polypropylene glycol di (meth) acrylate having 2 to 14 ethylene groups and 2 to 14 propylene groups, trimethylolpropane di (meth) acrylate, trimethylol Propane tri (meth) acrylate, EO-modified trimethylolpropane tri (meth) acrylate, PO-modified trimethylolpropane tri (meth) acrylate, EO / PO-modified trimethylolpropane tri (meth) acrylate, tetramethylol methanetri (meth) acrylate Examples include relate, tetramethylolmethane tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, and dipentaerythritol hexa (meth) acrylate. These can be used individually by 1 type or in combination of 2 or more types.

“EO” refers to “ethylene oxide”, and “PO” refers to “propylene oxide”. “EO modified” means having a block structure of ethylene oxide units (—CH ₂ CH ₂ O—), and “PO modified” means propylene oxide units (—CH ₂ CH (CH ₃ ) O—). It means having a block structure.

  Examples of the compound obtained by reacting a glycidyl group-containing compound with an α, β-unsaturated carboxylic acid include trimethylolpropane triglycidyl ether tri (meth) acrylate and 2,2-bis (4- (meth) acryloxy- 2-hydroxy-propyloxy) phenyl and the like. Examples of the α, β-unsaturated carboxylic acid include (meth) acrylic acid. These can be used individually by 1 type or in combination of 2 or more types.

  Examples of the urethane monomer or urethane oligomer include (meth) acrylic monomers having an OH group at the β-position and diisocyanates such as isophorone diisocyanate, 2,6-toluene diisocyanate, 2,4-toluene diisocyanate, and 1,6-hexamethylene diisocyanate. Addition reaction product with compound, tris ((meth) acryloxytetraethylene glycol isocyanate) hexamethylene isocyanurate, EO modified urethane di (meth) acrylate, EO or PO modified urethane di (meth) acrylate, carboxyl group-containing urethane (meth) acrylate Etc. These can be used individually by 1 type or in combination of 2 or more types.

  Furthermore, examples of the (meth) acrylic acid alkyl ester include (meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, (meth) acrylic acid butyl ester, and (meth) acrylic acid 2-ethylhexyl ester. It is done. These can be used individually by 1 type or in combination of 2 or more types.

  The photosensitive resin composition preferably contains a bisphenol A (meth) acrylate compound as the component (C) from the viewpoint of improving the resolution of the photosensitive resin composition and the flexibility of the cured film, and among them, alkyleneoxy It is more preferable to include a bisphenol A-based di (meth) acrylate compound having a group.

<(D) component: Photopolymerization initiator>
Specific examples of the photopolymerization initiator as component (D) include, for example, benzophenone, 4,4′-bis (dimethylamino) benzophenone (Michler ketone), 4,4′-bis (diethylamino) benzophenone, 4-methoxy- 4′-dimethylaminobenzophenone, 2-benzyl-2-dimethylamino-1-morpholinophenone) -butanone-1,2-ethylanthraquinone, phenanthrenequinone and other aromatic ketones, alkylanthraquinone and other quinones, benzoin methyl ether, Benzoin ethers such as benzoin ethyl ether and benzoin phenyl ether, benzoins such as methyl benzoin and ethyl benzoin, benzyl derivatives such as benzyl dimethyl ketal, 9-phenylacridine, 1,7-bis (9,9′-acridinyl) hepta And acridine derivatives such as N-phenylglycine, N-phenylglycine derivatives, and coumarin compounds. These can be used individually by 1 type or in combination of 2 or more types.

<(E) component: thermosetting agent>
Specific examples of the thermosetting agent that is component (E) include thermosetting compounds such as epoxy resins, phenol resins, urea resins, and melamine resins. Examples of the epoxy resin include bisphenol A type tertiary fatty acid-modified polyol epoxy resin; diglycidyl esters such as diglycidyl phthalate and diglycidyl tetrahydrophthalate, and diglycidyl amines such as diglycidyl aniline and diglycidyl toluidine. Etc. You may use these individually by 1 type or in combination of 2 or more types.

  Moreover, the block isocyanate compound which is a latent thermosetting agent can also be used as a thermosetting agent which is (E) component. Examples of the blocked isocyanate compound include polyisocyanate compounds blocked with a blocking agent such as an alcohol compound, a phenol compound, ε-caprolactam, an oxime compound, and an active methylene compound. Examples of blocked polyisocyanate compounds include 4,4-diphenylmethane disissocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, naphthalene 1,5-diisocyanate, o-xylene diisocyanate, m-xylene. Aromatic polyisocyanates such as diisocyanates and 2,4-tolylene dimers, aliphatic polyisocyanates such as hexamethylene diisocyanate, 4,4-methylenebis (cyclohexyl isocyanate) and isophorone diisocyanate, and alicyclic polyisocyanates such as bicycloheptane triisocyanate An aromatic polyisocyanate is preferable from the viewpoint of heat resistance, and an aliphatic polyisocyanate or an alicyclic polyisocyanate is preferable from the viewpoint of preventing coloring.

  In order for the photosensitive resin composition to have good flame retardancy, the content of the component (A) in the photosensitive resin composition is 35 to 70% by mass based on the total solid content of the photosensitive resin composition. It is preferable that it is 40-65 mass%. When the content of the component (A) is less than 35% by mass, the flame retardancy of the cured film tends to decrease, and when it exceeds 70% by mass, development with a dilute aqueous alkali solution tends to be difficult.

  In order to obtain good flame retardancy, the phosphorus content in the photosensitive resin composition is preferably 1.5 to 5.0% by mass based on the total solid content of the photosensitive resin composition. 2.0 to 4.5% by mass is more preferable. If the phosphorus content is less than 1.5% by mass, the flame retardancy of the cured film tends to decrease, and if it exceeds 5.0% by mass, the folding resistance and insulation reliability of the cured film decrease. Tend.

  The component (B) is preferably contained so that the phosphorus content is in the above range. Moreover, when using the phosphinic acid salt represented by the said General formula (2) as (B) component, the content should be 5-20 mass% on the basis of the solid content whole quantity of the photosensitive resin composition. preferable. If this content is less than 5% by mass, the flame retardancy of the cured film tends to be reduced, and if it exceeds 20% by mass, the flexibility of the cured film tends to be reduced.

Moreover, when using phosphate ester in combination with a phosphinic acid salt as (B) component, the content of the phosphate ester shall be 1-20 mass% on the basis of the solid content whole quantity of the photosensitive resin composition. Preferably, it is 3-10 mass%. When this content exceeds 20% by mass, the electrolytic corrosion property and the bleed-out property (peeling of the photosensitive resin composition) tend to be deteriorated.

  When the phenoxyphosphazene compound is used in combination with the phosphinate as the component (B), the content of the phenoxyphosphazene compound is 1 to 20% by mass based on the total solid content of the photosensitive resin composition. It is preferable that it is 3-15 mass%. When this content exceeds 20% by mass, the electrolytic corrosion property and the bleed-out property (peeling of the photosensitive resin composition) tend to be deteriorated.

  The content of the component (C) is preferably 7 to 30% by mass, and 10 to 25% by mass based on the total solid content of the photosensitive resin composition from the viewpoint of resolution and flame retardancy. It is more preferable. When the content of the component (C) is less than 7% by mass, the resolution tends to be inferior, and when it exceeds 30% by mass, the flame retardancy of the cured film tends to decrease.

  The content of the component (D) is preferably 0.1 to 10% by mass and preferably 0.2 to 5% by mass based on the total solid content of the photosensitive resin composition from the viewpoint of photosensitivity. Is more preferable.

  When the photosensitive resin composition contains the component (E), the content is 5 to 20% by mass based on the total solid content of the photosensitive resin composition from the viewpoint of flame retardancy and insulation reliability. It is preferably 8 to 15% by mass.

  In addition, the photosensitive resin composition of the present invention includes a dye such as malachite green, a photochromic agent such as leuco crystal violet, a plasticizer such as a thermochromic inhibitor or p-toluenesulfonamide, phthalocyanine blue, if necessary. Phthalocyanine-based organic pigments such as azo-based or inorganic pigments such as titanium dioxide, fillers made of inorganic pigments such as silica, alumina, talc, calcium carbonate or barium sulfate, antifoaming agents, stabilizers, adhesion-imparting agents , A leveling agent, an antioxidant, a fragrance, an imaging agent, or the like. These components are each preferably contained in an amount of about 0.01 to 20% by mass based on the total solid content of the photosensitive resin composition. Moreover, said component can be used individually by 1 type or in combination of 2 or more types.

  Furthermore, the photosensitive resin composition of the present invention may contain a solvent such as methanol, ethanol, acetone, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve, toluene, N, N-dimethylformamide, propylene glycol monomethyl ether or the like as necessary. It can melt | dissolve in a mixed solvent and can apply | coat as a solution of solid content about 30-70 mass%.

  The photosensitive resin composition of the present invention as described above is applied as a liquid resist on a metal surface such as copper, a copper-based alloy, iron, and an iron-based alloy, and then dried, and a protective film is provided as necessary. It can be used by coating or in the form of a photosensitive element described later.

  Moreover, the board | substrate which formed the cured film which consists of the photosensitive resin composition of this invention on flexible base materials, such as a polyimide, has the outstanding flame retardance. The photosensitive resin composition of the present invention does not contain a halogen-based compound or an antimony-based compound, and can make the cured film sufficiently high in flame retardancy. For example, it reduces the environmental load and toxicity of a printed wiring board. It becomes possible to do.

  Further, the photosensitive resin composition of the present invention can form a cured film having sufficient flame retardancy with high resolution, and can form a cured film having sufficient flexibility. It is preferably used for forming a permanent mask for a flexible printed wiring board.

(Photosensitive element)
Next, the photosensitive element using the photosensitive resin composition of the present invention described above will be described. FIG. 1 is a schematic cross-sectional view showing a preferred embodiment of the photosensitive element of the present invention. The photosensitive element 1 shown in FIG. 1 includes a support 10 and a photosensitive resin composition layer 14 provided on the support 10. The photosensitive resin composition layer 14 is a layer made of the above-described photosensitive resin composition of the present invention. Moreover, the photosensitive element 1 of this invention may coat | cover the surface F1 on the opposite side to the support body 10 on the photosensitive resin composition layer 14 with a protective film.

  The photosensitive resin composition layer 14 is prepared by dissolving the photosensitive resin composition of the present invention in the above solvent or mixed solvent to obtain a solution having a solid content of about 30 to 70% by mass, and then applying the solution onto the support 10. Is preferably formed.

  Although the thickness of the photosensitive resin composition layer 14 varies depending on the application, it is preferably 10 to 100 μm and more preferably 20 to 60 μm in thickness after drying after removing the solvent by heating and / or hot air blowing. preferable. If the thickness is less than 10 μm, it tends to be difficult to apply industrially, and if it exceeds 100 μm, the above-described effects produced by the present invention tend to be reduced, and in particular, flexibility and resolution tend to decrease.

  Examples of the support 10 included in the photosensitive element 1 include polymer films having heat resistance and solvent resistance such as polyethylene terephthalate, polypropylene, polyethylene, and polyester.

  The thickness of the support 10 is preferably 5 to 100 μm, and more preferably 10 to 30 μm. If the thickness is less than 5 μm, the support tends to be broken when the support is peeled off before development, and if it exceeds 100 μm, the resolution and flexibility tend to decrease.

  The photosensitive element 1 consisting of two layers of the support 10 and the photosensitive resin composition layer 14 as described above or the photosensitive element consisting of three layers of the support 10, the photosensitive resin composition layer 14 and the protective film is as follows. For example, it may be stored as it is, or it can be wound around a roll core and stored after interposing a protective film.

  The method for forming a resist pattern using the photosensitive element of the present invention includes a removing step of removing the protective film from the photosensitive element as necessary, the photosensitive element comprising the photosensitive resin composition layer and the support. A lamination process for sequentially laminating on a circuit forming substrate, and actinic rays are irradiated to a predetermined portion of the photosensitive resin composition layer through a support as necessary, and a photocured portion is formed on the photosensitive resin composition layer. It includes an exposure step to be formed and a development step for removing the photosensitive resin composition layer other than the photocured portion. The circuit-forming substrate is an insulating layer and a conductor layer (copper, copper-based alloy, iron-based alloy such as nickel, chromium, iron, stainless steel, preferably copper, copper-based alloy) formed on the insulating layer. , Made of an iron-based alloy).

  Examples of the laminating method in the laminating step after the removing step of removing the protective film as necessary include a method of laminating by pressing the photosensitive resin composition layer on the circuit forming substrate while heating. The atmosphere during the lamination is not particularly limited, but the lamination is preferably performed under reduced pressure from the viewpoint of adhesion and followability. The surface to be laminated is usually the surface of the conductor layer of the circuit forming substrate, but may be a surface other than the conductor layer.

  The heating temperature of the photosensitive resin composition layer is preferably 70 to 130 ° C., the pressure bonding pressure is preferably about 0.1 to 1.0 MPa, and the ambient atmospheric pressure is more preferably 4000 Pa or less. These conditions are not particularly limited. Further, if the photosensitive resin composition layer is heated to 70 to 130 ° C. as described above, it is not necessary to pre-heat the circuit forming substrate in advance, but in order to further improve the laminating property, Pre-heat treatment of the substrate can also be performed.

  After the lamination is completed in this manner, a photocured portion is formed by irradiating a predetermined portion of the photosensitive resin composition layer with actinic rays in the exposure step. Examples of the method for forming the photocured portion include a method of irradiating an actinic ray in an image form through a negative or positive mask pattern called an artwork. At this time, when the support present on the photosensitive resin composition layer is transparent, it can be irradiated with actinic rays as it is, but when opaque, the photosensitive resin composition is removed after removing the support. Irradiate the layer with actinic rays.

  As the light source of actinic light, a known light source such as a carbon arc lamp, a mercury vapor arc lamp, an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a xenon lamp, or the like that can effectively emit ultraviolet rays can be used. Moreover, what can radiate | emit visible light effectively, such as a flood bulb for photography, a solar lamp, can also be used.

  Next, after exposure, when a support is present on the photosensitive resin composition layer, after removing the support, in the development process, a photosensitive resin other than the photocured portion by wet development, dry development, or the like. The composition layer is removed and developed to form a resist pattern.

  In the case of wet development, development is performed using a developer such as an alkaline aqueous solution by a known method such as spraying, rocking immersion, brushing, or scraping. As the developer, a developer that is safe and stable and has good operability is used. For example, a dilute solution (1 to 5% by mass aqueous solution) of sodium carbonate at 20 to 50 ° C. is used.

  For example, when the resist pattern obtained by the above-described forming method is used as a solder resist for a printed wiring board, a high pressure is used for the purpose of improving solder heat resistance, chemical resistance, etc. as the solder resist after completion of the development process. It is preferable to perform ultraviolet irradiation with a mercury lamp or heating with an oven.

In the case of irradiating ultraviolet rays, the irradiation amount can be adjusted as necessary. For example, the irradiation can be performed at an irradiation amount of about 0.2 to 10 J / cm ² . Moreover, when heating, it is preferable to carry out for about 15 to 90 minutes in the range of about 100-170 degreeC. Furthermore, both ultraviolet irradiation and heating may be performed, and after one of them is performed, the other can be performed.

  The resist pattern obtained by the above-described forming method is preferably used as a permanent mask formed on a printed wiring board. Since the cured film formed from the photosensitive resin composition of the present invention has excellent flame retardancy, it is effective as a permanent mask for a printed wiring board that also serves as a protective film for wiring after soldering to the substrate. is there.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example.

(Examples 1-4 and 6-7, Reference Example 5 , Comparative Examples 1-4)
First, a solution of the photosensitive resin composition was obtained by mixing each component shown in Table 1 at a solid content ratio (mass basis) (where methyl ethyl ketone is a mass basis as a liquid).

  In Table 1, component (A-1) is biphenyl type epoxy acrylate (manufactured by Nippon Kayaku Co., Ltd., trade name “ZCR-1569H”, novolak type acid-modified vinyl group-containing epoxy resin having a biphenyl skeleton, acid value = 98, Mw = 4500), and the component (A-2) is a bisphenol A type epoxy acrylate (manufactured by Nippon Kayaku Co., Ltd., trade name “ZAR-2001H”, acid value = 103, Mw = 13000), The component A-3) is bisphenol F type epoxy acrylate (manufactured by Nippon Kayaku Co., Ltd., trade name “ZFR-1516”, acid value = 73, Mw = 11000).

  The component (B-1) is a phosphinic acid salt (manufactured by Clariant, trade name “EXOLIT OP 935”, phosphorus content = 23 mass%), and the component (B-2) is a phosphate ester (manufactured by Adeka). , Trade name “ADK STAB FP-600”, phosphorus content = 8.9 mass%), and component (B-3) is a phenoxyphosphazene compound (manufactured by Otsuka Chemical Co., Ltd., trade name “SPB-100”, phosphorus Content = 13 mass%).

  The component (C) is bisphenol A polyoxyethylene dimethacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name “BPE-10”).

  The component (D) is 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 (trade name “I-369” manufactured by Ciba Specialty Chemicals).

  The component (E) is a 75% by mass methyl ethyl ketone solution (trade name “BL3175”, manufactured by Sumika Bayer Urethane Co., Ltd.) of an isocyanurate methylethylketone oxime block having hexamethylene diisocyanate as a base isocyanate.

  In the table, the acrylic resin was polymerized by a conventional method in a toluene / methyl cellosolve (mass ratio = 2/3) solution using methacrylic acid / ethyl acrylate / methyl methacrylate / styrene as a copolymerization component. Is a copolymer having a weight average molecular weight of 100,000.

注）表１中の値は、各成分の固形分の配合比である（メチルエチルケトンは除く）。
また、表中の記号「−」は、該当する成分を含有していないことを示す。

Note) The values in Table 1 are the blending ratio of the solid content of each component (excluding methyl ethyl ketone).
Further, the symbol “-” in the table indicates that the corresponding component is not contained.

[Production of photosensitive element]
The photosensitive resin composition solutions of Examples 1 to 4 and 6 to 7, Reference Example 5 and Comparative Examples 1 to 4 were mixed with a 16 μm-thick polyethylene terephthalate film (manufactured by Teijin Limited, trade name “G2- 16 ”) and separately, each was uniformly coated to form a photosensitive resin composition layer, which was dried at 100 ° C. for 10 minutes using a hot air convection dryer. The film thickness after drying of the photosensitive resin composition layer was 38 μm.

  Next, a polyethylene film (manufactured by Tamapoly Co., Ltd., trade name “NF-13”) is bonded as a protective film on the surface of the photosensitive resin composition layer opposite to the side in contact with the support. Got.

[Preparation of evaluation laminate]
The copper surface of a flexible printed wiring board substrate (trade name “F30VC1” manufactured by Nikkan Kogyo Co., Ltd.) obtained by laminating a 18 μm thick copper foil on a polyimide base material was acid-washed with hydrochloric acid, washed with water, and dried.

  Using a continuous vacuum laminator (manufactured by Hitachi Chemical Co., Ltd., trade name “HLM-V570”) on this flexible printed wiring board substrate, a heat shoe temperature of 100 ° C., a laminating speed of 0.5 m / min, and an atmospheric pressure of 4000 Pa or less, Under the condition of a pressure bonding pressure of 0.3 MPa, the obtained photosensitive element was laminated with the photosensitive resin composition layer on the copper foil side while peeling the polyethylene film to obtain a laminate for evaluation.

[Evaluation of light sensitivity]
A phototool having a stove 21-step tablet as a negative is closely attached to the obtained laminate for evaluation, and an HMW-201GX type exposure machine manufactured by Oak Manufacturing Co., Ltd. is used. The exposure was performed with an energy amount such that the number of steps remaining after development was 8.0.

  Subsequently, after leaving still at room temperature for 1 hour and peeling off a PET film, it developed by spraying 1 mass% sodium carbonate aqueous solution of 30 degreeC for 40 second, and heated (dried) at 80 degreeC for 10 minutes. The above-mentioned energy amount at the time of exposure was used as a numerical value for evaluating the photosensitivity. The lower this value, the higher the photosensitivity. The results are shown in Table 2.

[Resolution evaluation]
A phototool having a stove 21-step tablet and a phototool having a wiring pattern with a line width / space width of 30/30 to 200/200 (unit: μm) as a negative for resolution evaluation are provided on the evaluation laminate. Using the above-described exposure apparatus, the exposure was performed with an energy amount such that the number of remaining steps after development of the stove 21-step tablet was 8.0.

  Subsequently, after leaving still at room temperature for 1 hour and peeling off a PET film, it developed by spraying 1 mass% sodium carbonate aqueous solution of 30 degreeC for 40 second, and heated (dried) at 80 degreeC for 10 minutes. Here, the resolution was evaluated based on the smallest value (unit: μm) of the space width between the line widths in which a rectangular resist shape was obtained by development processing. It shows that it is excellent in the resolution, so that this value is small. The results are shown in Table 2.

[Production of evaluation FPC]
On the obtained laminate for evaluation, a photo tool having a stove 21-step tablet and a photo tool having a wiring pattern as a negative for reliability evaluation of the coverlay are brought into close contact, and the exposure machine described above is used. Then, exposure was performed with an energy amount such that the number of remaining steps after development of the stove 21-step tablet was 8.0.

Next, after standing at room temperature for 1 hour, the polyethylene terephthalate on the laminate was peeled off, spray development was performed under the same developer and development conditions as in the photosensitivity evaluation, and heated (dried) at 80 ° C. for 10 minutes. . Subsequently, the FPC for evaluation in which the coverlay was formed by performing ultraviolet irradiation with an energy amount of 1 J / cm ² using an ultraviolet irradiation device manufactured by Oak Manufacturing Co., Ltd., and further performing heat treatment at 160 ° C. for 60 minutes. Obtained.

[Evaluation of flexibility (folding resistance)]
The evaluation FPC obtained as described above was repeatedly bent 180 ° by goby folding, and the number of times until a crack occurred in the coverlay at that time was determined and evaluated according to the following criteria. The presence or absence of cracks was confirmed with a microscope. The results are shown in Table 2.
A: No cracks are observed in the coverlay even after being bent 5 times or more,
B: The number of times of bending until cracking is 3 to 4 times,
C: The number of times until a crack is generated is 2 or less.

[Bleed-out evaluation]
The evaluation FPC obtained as described above was pressed in the thickness direction for 30 minutes under the conditions of a press temperature of 160 ° C. and a press pressure of 20 kgf using a 30-t hand press machine (manufactured by Toyo Seiki Seisakusho Co., Ltd.). The presence or absence of bleeding of the photosensitive resin composition component from the cover lay at that time was visually observed and evaluated according to the following criteria. That is, “A” indicates that the photosensitive resin composition component does not exude from the coverlay, “B” indicates that the photosensitive resin composition component exudes slightly, and “B” indicates that the photosensitive resin composition component. Those with significant bleeding were evaluated as “C”. The results are shown in Table 2.

[Evaluation of flame retardancy]
The copper foil of the copper foil-clad laminate (manufactured by Nippon Steel Chemical Co., Ltd., product name “ESPANEX MB” series) was removed by etching to obtain a PI film having a thickness of 25 μm. Next, on both sides of the PI film, using a continuous vacuum laminator (manufactured by Hitachi Chemical Co., Ltd., trade name “HLM-V570”), a heat shoe temperature of 100 ° C., a laminating speed of 0.5 m / min, an atmospheric pressure of 4000 Pa or less, Under the condition of a pressure bonding pressure of 0.3 MPa, the above-described photosensitive element was laminated with the photosensitive resin composition layer on the PI film side while peeling the polyethylene film to obtain a laminate.

  Next, using a HNW-201GX type exposure machine manufactured by Oak Seisakusho Co., Ltd., the photosensitive resin composition layer of the photosensitive element was exposed to a remaining step number of 8 after development of the stove 21-step tablet. The above energy amount was set to 0. Then, after leaving still at room temperature for 1 hour and peeling a polyethylene terephthalate film from a laminated body, the 1 mass% sodium carbonate aqueous solution of 30 degreeC is sprayed on a laminated body for 40 second, and it develops, and it heats at 80 degreeC for 10 minutes (Dry).

Next, the photosensitive resin composition layer of the laminate is irradiated with ultraviolet rays with an energy amount of 1 J / cm ² using an ultraviolet irradiation device manufactured by Oak Manufacturing Co., Ltd., and further subjected to heat treatment at 160 ° C. for 60 minutes, A sample for flame retardancy evaluation in which a coverlay was formed was obtained.

  This flame retardant evaluation sample was subjected to a thin material vertical combustion test based on the UL94 standard. Evaluation was expressed as VTM-0, VTM-1, or VTM-2 based on the UL94 standard. The results are shown in Table 2. Note that “NOT” in Table 2 indicates that the flame retardancy evaluation sample did not correspond to VTM-0, VTM-1, and VTM-2 in the combustion test and was completely burned.

As is clear from the results shown in Table 2, according to the photosensitive resin compositions of Examples 1 to 4 and 6 to 7 and Reference Example 5 , it was confirmed that sufficient photosensitivity and resolution could be obtained. Moreover, it was confirmed that the laminated board provided with the cured film formed from the photosensitive resin composition of Examples 1-4 and 6-7, and the reference example 5 has sufficient flame retardance. Furthermore, it was confirmed that the cured film formed from the photosensitive resin composition of Examples 2, 3 and 6 to 7 and Reference Example 5 has excellent flexibility (folding resistance).

  As described above, according to the present invention, a photosensitive resin composition capable of forming a cured film having excellent alkali developability and excellent flame retardancy, and a photosensitive element using the same are provided. can do.

Claims (7)

(A) a novolac acid-modified vinyl group-containing epoxy resin having a biphenyl skeleton;
(B) a phosphorus-containing compound;
(C) a photopolymerizable compound having at least one ethylenically unsaturated group in the molecule;
(D) a photopolymerization initiator;
Contain,
The photosensitive resin composition in which the said (B) phosphorus containing compound contains the phosphinic acid salt represented by following General formula (2) .

[In Formula (2), A and B each independently represent a linear or branched alkyl group having 1 to 6 carbon atoms or an aryl group, and M represents Mg, Ca, Al, Sb, Sn. , Ge, Ti, Zn, Fe, Zr, Ce, Bi, Sr, Mn, Li, Na, and K. m represents an integer of 1 to 4. ] The (A) epoxy resin is a reaction between (a) an epoxy resin represented by the following general formula (1), (b) an unsaturated group-containing monocarboxylic acid, and (c) a polybasic carboxylic acid anhydride. The photosensitive resin composition of Claim 1 containing the acid-modified vinyl group containing epoxy resin which is a product.

[In Formula (1), R ¹ and R ² each independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an aryl group, and n represents an integer of 0 to 50. In formula (1), a plurality of R ¹ and R ² may be the same or different. ]   The photosensitive resin composition according to claim 1 or 2, further comprising (E) a thermosetting agent. The photosensitive resin composition as described in any one of Claims 1-3 with which the said (B) phosphorus containing compound contains phosphate ester. (B) the phosphorus-containing compound comprises a phenoxy phosphazene compound, the photosensitive resin composition according to any one of claims 1-4. The photosensitive resin composition as described in any one of Claims 1-5 which is for forming the cured film used as a permanent mask on a flexible substrate. A photosensitive element provided with a support body and the photosensitive resin composition layer which consists of a photosensitive resin composition as described in any one of Claims 1-6 formed on this support body.

Images